U.S. Pat. No. 2,621,501 is directed to a permanent size indicia for clothes, such as socks, in which circular areas are knit in the heels of the socks. The circular areas are knit with yarns which are different in color from the color of the yarn knit throughout the remainder of the sock. The yarns used in knitting the circular areas in the heels of the socks may be either yellow, blue or red and indicate the particular size of the sock on which one of these colored circles appear. The knit circles of different colors of yarn are also helpful in pairing socks after laundering. However, it is difficult to knit circular areas of different colored yarns in the heel portion of socks, without requiring extensive modification of the knitting machine on which the socks are knit. Also, the formation of circular size indicating areas in the heels of socks may not be readily visible when the socks are folded for storage.